This invention relates to a climber to be used by professional utility polemen, lumberjacks and tree trimmers for climbing trees and wood poles.
Climbers as used by professionals consist of a stirrup which supports the instep of the user, a shank which is connected to the stirrup which is thrust into the tree or pole. A pad for protecting the leg is connected to the upper end of the shank. The shank also provides vertical stability to the gaff and for this reason, the shank must be attached to the inner side of the leg. The prior art assumed that vertical stability of the shaft was required for safety and that the upper end of the shank should be as rigidly attached to the pad as possible.
Holding the shank rigid is certainly desirable for climbing but the problem arises when the workman must set the gaffs into the tree or pole and then stand on the stirrups for long periods of time while he accomplishes his work. The shaft rigidly attached to the leg serves as a non-yielding cast and ignores the fact that as the workman bends, leans, stretches, etc., he moves his leg relative to the foot about the ankle. When the workman moves his foot on the stirrup, the leg moves in relation to the stirrup and shank and something has to give. With the state-of-the-art climbers in which the shaft is rigidly attached to the pads, it is the pad that moves in relation to the calf of the leg and this movement causes a chafting of the leg. While chafing can be tollerated for a short time, persistent chafing day after day can cause serious discomfort and even injury to the leg. Prolonged chafing can make wearing climbers so uncomfortable that the workmen cannot wear the climbers until the leg heals.
Leather pads which attempt to prevent injury are shown in Katz, U.S. Pat. No. 1,727,237 (1929); Smith U.S. Pat. No. 3,640,358 (1972) and Joseph U.S. Pat. No. 3,867,998 (1975). Chafing is a problem with these leather pads.
Attempts to rigidize the leather pads by facing them with metal and rigidly attaching the shafts to the metal are taught by Detering U.S. Pat. No. 2,297,136 (1942) and McIntire U.S. Pat. No. 2,760,705 (1983). Again, chafing is a problem even though it is somewhat lessened by the addition of felt and sponge.